Purpose: Depression in older females is a significant and growing problem. Females who experience life stressors across the life span are at higher risk for developing problems with depression than their male counterparts. The primary aim of this study was (a) to examine gender-specific differences in the correlates of depression in older primary care patients based on baseline and longitudinal analyses; and (b) to examine the longitudinal effect of biopsychosocial risk factors on depression treatment outcomes in different models of behavioral healthcare (i.e., integrated care and enhanced referral). Method: This study used a quantitative secondary data analysis with longitudinal data from the Primary Care Research in Substance Abuse and Mental Health for Elderly (PRISM-E) study. A linear mixed model approach to hierarchical linear modeling was used for analysis using baseline assessment, and follow-up from three-month and six-month. Results: For participants diagnosed with major depressive disorder female gender was associated with increased depression severity at six-month compared to males at six-month. Further, the interaction between gender and life stressors found that females who reported loss of family and friends, family issues, money issues, medical illness was related to higher depression severity compared to males whereas lack of activities was related to lower depression severity among females compared to males. Conclusion: These findings suggest that gender moderated the relationship between specific life stressors and depression severity similar to how a protective factor can impact a person’s response to a problem and reduce the negative impact of a risk factor on a problem outcome. Therefore, life stressors may be a reliable predictor of depression for both females and males in either behavioral health treatment model. This study concluded that life stressors influence males basic comfort, stability, and survival whereas life stressors influence females’ development, personal growth, and happiness; therefore, life stressors may be a useful component to include in gender-based screening and assessment tools for depression.

Change in educational settings is a complex and multifaceted process that commonly implies change in teaching practices. Different initiatives have shown the significance of teachers and their perceptions when change in teaching practices is intended. Additionally, various factors may influence change in teaching practices at three different moments: before it happens, during, and after its implementation. Considering teachers' perceptions, I studied different factors that may be related to positive change in teaching practices. I studied the relationship between three groups of factors and positive change in teaching practices: motivational factors, including teachers' self-efficacy and autonomy; learning opportunities that include professional development, feedback, and leadership; and the academic and community domains as part of the school climate factor. In particular, I answered the following research question: To what extent do learning opportunities, teacher motivational factors, and school climate predict positive change in teaching practices? In this study I posited that teacher factors such as self-efficacy and school factors such as leadership influence positive change in teaching practices. I also posited that school factors influence the relationship between teacher factors and positive change in teaching practices. To study these relationships, I analyzed data from the Teaching and Learning International Survey (TALIS). This survey provides clustered data: teachers are clustered by schools and schools by countries. I used multilevel modeling statistical methods (i.e., a two-level hierarchical linear model) to examine the Colombian and United Stated datasets. Before estimating the hierarchical linear models, I conducted an exploratory factor analysis (EFA) to identify the teacher-level variables. One follow-up EFA focused on teacher self-efficacy yielded three variables that allowed me to focus on three specific teaching tasks: managing student behavior, motivating students, and varying instructional strategies. I found that learning opportunities, motivational factors, and school climate predict positive change in teaching practices. Learning opportunities, such as feedback from the principal has a stronger effect than feedback from colleagues. The impact of feedback from the principal has significant unnoticeable variability across schools, and it is negatively influenced by the feedback received by the teachers at the same school. Additionally, teachers' self-efficacy in different teaching tasks predicts positive change, however, these relationships differ by country. Finally, distributed leadership as part of school climate is a significant predictor of positive change that also affects it by influencing teacher interactions positively. Implications of these findings are also discussed as it relates to the existing literature and the educational system in each of the two countries. / Doctor of Philosophy / Over many decades there have been different initiatives in education to improve teaching. Unfortunately, many of those efforts have had unsuccessful results, although they are solid proposals. Thus, change itself has become a focus of study. My study focuses on factors that may influence positive change in teaching practices. I focus on three groups of factors: learning opportunities, motivational factors, and school climate. For learning opportunities, I studied the participation of teachers in professional development, feedback to teachers from different educational community members, and interactions between teachers. For motivational factors, I focused on teachers' autonomy and self-efficacy. Finally, for school climate, I studied factors associated with leadership, interactions between teachers at the same school, and participation of teachers from the same school in professional development. I analyzed data from the Teaching and Learning International Survey (TALIS). TALIS is an international survey administered to teachers and principals worldwide. I considered TALIS data from Colombia and the US. Within each country, teachers are grouped by schools, that is, teacher are nested within schools. In this study, teachers are considered the level-one unit, and schools, the level-two units. Therefore, I analyzed the data using a statistical method known as Hierarchical Linear Modelling. This method allowed me to identify different relationships: between teacher-level factors and positive change, between school-level factors and positive change, and between school-level factors and the relationship between teacher factors and positive change. I was also able to partition the variance associated with these relationships between teachers and between schools. I found that learning opportunities, motivational factors, and school climate are predictors of positive change in teaching practices. This means that teachers are more likely to implement changes in their teaching practices if they: participate in professional development, interact with their colleagues, receive feedback from the principal and their colleagues, have a high level of self-efficacy for different teaching tasks, and belong to a school where leadership is well distributed among different stakeholders. In particular, feedback could have a stronger impact if it is based on different sources of information. Finally, I discuss the implications of these findings and conclusions that lead to a better understanding of these relationships.

My Masters research aims to deepen our understanding of the behaviour of robust methods in logistic regression. Logistic regression is a special case of Generalized Linear Modelling (GLM), which is a powerful and popular technique for modelling a large variety of data. Robust methods are useful in reducing the effect of outlying values in the response variable on parameter estimates. A literature survey shows that we are still at the beginning of being able to detect extreme observations in logistic regression analyses, to apply robust methods in logistic regression and to present informatively the results of logistic regression analyses. In Chapter 1 I have made a basic introduction to logistic regression, with an example, and to robust methods in general. In Chapters 2 through 4 of the thesis I have described traditional methods and some relatively new methods for presenting results of logistic regression using powerful visualization techniques as well as the concepts of outliers in binomial data. I have used different published data sets for illustration, such as the Prostate Cancer data set, the Damaged Carrots data set and the Recumbent Cow data set. In Chapter 4 I summarize and report on the modem concepts of graphical methods, such as central dimension reduction, and the use of graphics as pioneered by Cook and Weisberg (1999). In Section 4.6 I have then extended the work of Cook and Weisberg to robust logistic regression. In Chapter 5 I have described simulation studies to investigate the effects of outlying observations on logistic regression (robust and non-robust). In Section 5.2 I have come to the conclusion that, in the case of classical or robust multiple logistic regression with no outliers, robust methods do not necessarily provide more reasonable estimates of the parameters for the data that contain no st~ong outliers. In Section 5.4 I have looked into the cases where outliers are present and have come to the conclusion that either the breakdown method or a sensitivity analysis provides reasonable parameter estimates in that situation. Finally, I have identified areas for further study.

No description available.

Neighbourhood stressors have an incubating effect for a variety of health-related disorders involving children. It is of interest is to determine if asthma prevalence is greater amongst school children at age 7-8 resident of chronic stress neighbourhoods in Winnipeg, after adjusting for family history of asthma and socioeconomic status. The urban component of children (1472 entire; 698 birth home) extracted from the Study of Asthma, Genes and the Environment (SAGE) Survey administered in 2002-2003 to a birth cohort from 1995 in Manitoba. Dichotomous parent report of child asthma from the SAGE Survey nested within birth cohort was geocoded by postal code, which allowed designation of neighbourhood in hierarchical linear modelling. Children living in census tracts assigned low SES scores by compositional stressors were found to have a decreased odds of parent report of asthma, while those inhabiting profiles with high contextual crime rates were at increased risk.

L'assemblage des éléments de structures en bois de dimensions standard comme des poutres massives ou composites s'effectue très fréquemment avec des ancrages métalliques cloués. Ces éléments en tôle pliée formés à froid peuvent être mis sur le marché Européens lorsqu'un ATE est obtenu à partir des recommandations de l'ETAG 015. Le développement ainsi que la caractérisation de la résistance de ces ancrages s'effectue jusqu'à présent dans la société CULLEN Building Products par des essais longs et coûteux. En alternative à cette démarche, ce travail présente une démarche permettant de modéliser le comportement de ces assemblages par la méthode des éléments finis. En premier lieu une étude est conduite sur les types d'aciers utilisés et sur l'influence de la phase de formage sur la résistance de l'ancrage. Il est alors montré qu'il n'est pas nécessaire d'intégrer l'état d'écrouissage produit par le pliage et que la modélisation peut débuter à partir de la géométrie finale à l'aide d'éléments coques. En second lieu une modélisation simplifiée du comportement des pointes est proposée. Les paramètres nécessaires à sa mise en oeuvre sont identifiés. Le modèle est mis en oeuvre pour simuler le comportement d'un assemblage tôle sur bois à une seule pointe. Les résultats sont confrontés à des résultats expérimentaux. La modélisation de l'ancrage étant forcément tridimensionnelle, une modélisation non linéaire du bois 3D est proposée en idéalisant le bois comme une structure. Cette structure est composée de cube de mousse (crushable foam) associé à des poutres élasto plastique qui donne à cet édifice son caractère fortement orthotrope. Ce modèle structurale du bois est mis en oeuvre pour modéliser le cisaillement de barreaux de bois, de la compression transversale sur appuis de poutre, des essais d'enfoncement de broches et un assemblage traditionnel par embrèvement. Ces modélisations permettent de montrer les capacités du modèle à décrire les comportements et de définir ses limites. Dans une dernière partie, l'ancrage, les pointes et le bois sont rassemblés pour constitué trois modèles d'ancrages caractéristiques les plus complexes de la production CULLEN. Les résultats obtenus sont confrontés à des résultats expérimentaux conduits en laboratoire. Enfin les modélisations sont utilisés pour expliquer le comportement interne des ancrages au cours du chargement jusqu'à l'atteinte de la rupture / The assembly of various elements of timber structures of standard dimensions such as timber beams or composite beams is often achieved by nailed steel connectors. These folded steel elements obtained by cold forming can be launched on the European market once an ETA is delivered regarding the recommendations of the ETAG 015. Up to now, the development and the characterisation of the strength of these connectors have been done within the company: CULLEN Building Products by lengthy and costly experimental tests. As an alternative to this procedure, this work presents an approach which enables modelling the behaviour of these connections by the finite element method. In the first place the influence of the type of steel used and the forming process on the strength of these hangers was studied. It is shown that it is not necessary to take into account the hardening produced by the forming of the steel so that the modelling can be achieved from the final geometry by shell elements. Secondly a simplified model of the behaviour of the nails is proposed. The parameters necessary for its implementation are identified. The model is then used to simulate the behaviour of the connection of a steel plate to timber by a single nail. These results are then confronted with the experimental results. As the model is necessarily 3 dimensional, a 3D non linear model is proposed for the timber by considering it as a structure. This structure is composed of cubes of crushable foam which are associated with elasto-plastic beams to give this structure its highly orthotropic behaviour. This structural model of wood is implemented to model the shear of timber bars, transversal compression where beams are supported, embedment tests of steel dowels and a traditional bird's mouth assembly. These various models show the capacities of this structural model to describe timber's complex behaviours; they also define the limits of this modelling. In the last section, the hanger, the nails and the timber are assembled in order to constitute the models for three characteristic and complex hangers of CULLEN's production. The results obtained are confronted with the experimental results. Finally, the models are used to explain the internal behaviour of these hangers at various loads up to their failure

Philosophiae Doctor - PhD / The educational landscape in South Africa is unique and has also seen many changes since the dawn of democracy more than 20 years ago. The apartheid education system was marred by severe inequalities between schools and, for this reason, the democratic government post 1994 established a number of policies and interventions in an attempt to improve access, equity and quality between schools. The country has made significant advances in improving access to education. This is reflected in the Millennium Development Goals progress indicators showing that, as of 2013, almost all learners between the ages of 7 and 15 were enrolled in schools. While great strides have also been made with regard to equity, evidence shows that many schools in South Africa are still largely inequitable. Education quality, however, is an area that is still of grave concern and the matter requires much attention from educational stakeholders. International studies, such as the Trends in International Mathematics and Science Study (TIMSS) and the Progress in International Reading Literacy Study (PIRLS), use learner performance to measure the quality of the system. Such studies consistently report that South Africa is performing poorly and that large inequalities still exist between schools in the country. Improved quality is associated with effective schools and, in South Africa, only 20% of schools have been found to be functional or effective. Much of research focussed on school effectiveness, both nationally and internationally, however has been explained by factors in the school, including the appropriateness of curriculum content, infrastructure, resources in the school and teacher content knowledge. These factors have been found to be strongly correlated with effective schools.

Demands for including more functions such as haptic guiding in power steering systems in road vehicles have increased with requirements on new active safety and comfort systems. Active safety systems, which have been proven to have a positive effect on overall vehicle safety, refer to systems that give the driver assistance in more and less critical situations to avoid accidents. Active safety features are going to play an increasingly important roll in future safety strategies; therefore, it is essential that sub systems in road vehicles, such as power steering systems, are adjusted to meet new demands. The traditional Hydraulic Power Assisted Steering, HPAS, system, cannot meet these new demands, due to the control unit's pure hydro-mechanical solution. The Active Pinion concept presented in this thesis is a novel concept for controlling the steering wheel torque in future active safety and comfort applications. The concept, which can be seen as a modular add-on added to a traditional HPAS system, introduces an additional degree of freedom to the control unit. Different control modes used to meet the demands of new functionality applications are presented and tested in a hardware-in-the-loop test rig. This thesis also covers various aspects of hydraulic power assisted steering systems in road vehicles. Power steering is viewed as a dynamic system and is investigated with linear and non-linear modeling techniques. The valve design in terms of area gradient is essential for the function of the HPAS system; therefore, a method involving optimization has been developed to determine the valve characteristic. The method uses static measurements as a base for calculation and optimization; the results are used in both linear and the non-linear models. With the help of the linear model, relevant transfer functions and the underlying control structure of the power steering system have been derived and analyzed. The non-linear model has been used in concept validation of the Active Pinion. Apart from concept validation and controller design of the active pinion, the models have been roven effective to explain dynamic phenomena related to HPAS systems, such as the chattering phenomena and hydraulic lag. / The printed version and the electronic version differ in that the electronic version contains two built in video films (see page 78 and page 89).

Emotionally Focused Couple Therapy (EFT; Johnson, 2004) addresses relationship distress by facilitating the development of new patterns of interaction between partners. These new patterns of interaction are based on partners' vulnerable acknowledgement and expression of attachment needs. Partners' engagement in these new patterns of interaction is thought to improve their relationship-specific attachment bond. Although previous studies have shown EFT to result in excellent relationship satisfaction outcomes (Johnson, Hunsley, Greenberg & Schindler, 1999), research had yet clearly to demonstrate if and how EFT facilitates increases in partners' relationship-specific models attachment security over the course of therapy. To address this research gap, the current study employed Hierarchical Linear Modelling (HLM; Singer & Willet, 2003) to investigate the pattern of change in couples' (n=32) self-reported relationship satisfaction and relationship-specific attachment over the course of EFT. Couples reported significant linear increases in their relationship satisfaction and significant linear decreases in their relationship-specific attachment avoidance over the course of therapy. Couples who completed the blamer-softening therapeutic change event (n=16) demonstrated significant linear decreases in their relationship-specific attachment anxiety after completing this event. Decreases in relationship-specific attachment anxiety predicted increases in couples' relationship satisfaction over the course of therapy. Couples also demonstrated significant increases in the security of their pre-post-therapy relationship-specific attachment behaviour, as coded Secure Base Scoring System (Crowell, Treboux, Gao, Fyffe, Pan & Waters, 2002). The current study also used HLM (Singer & Willet, 2003) to examine how the completion of blamer-softening impacted softened couples' relationship-specific attachment anxiety, and whether the completion of blamer-softening had a similar impact on softened couples' relationship-specific attachment avoidance and relationship satisfaction. Softened couples reported an immediate increase in relationship satisfaction and immediate decrease relationship-specific attachment avoidance at the softening session. Further, softened couples' post-softening decreases in relationship-specific attachment anxiety were initially preceded by an increase at the softening session. These results provided an understanding of how EFT leads to increases in couples' relationship-specific attachment security. These results provide support for the use of attachment theory in the treatment of relationship distress, and also provide an illustration of how attachment can shift over the course of a therapeutic intervention.

Objectives: To investigate factors influencing consumption of traditional foods (e.g., wild game, fish) and concerns about environmental contaminants among schoolchildren of the Mushkegowuk Territory First Nations (Moose Factory, Fort Albany, Kashechewan, Attawapiskat, and Peawanuck). Study Design: Cross-sectional data collection from a Web-based Eating Behaviour Questionnaire (WEB-Q). Methods: Schoolchildren in grades 6-12 (n = 262) responded to four of the WEB-Q questions: (1) Do you eat game? (2) How often do you eat game? (3) How concerned are you about the environmental contaminants in the wild game and fish that you eat? (4) I would eat more game if...[ six response options]. Data were collected from 2004-2009. Hierarchical log-linear modelling (LLM) was used for analyses of multi-way frequency data. Results: Of the school children answering the specific questions: 174 consumed game; 95 reported concerns about contaminants in game; and 84 would increase their game consumption if it were more available in their homes. LLM revealed significant differences between communities; schoolchildren in Moose Factory consumed game ???rarely or never??? at greater than expected frequency, and fewer than expected consumed game ???at least once a day.??? Schoolchildren in Kashechewan had greater frequency of daily game consumption and few were concerned about contaminants in game. Using LLM, we found that sex was an insignificant variable and did not affect game consumption frequency or environmental contaminant concern. Conclusion: The decreasing importance of the traditional diet was most evident in Moose Factory, possibly due to its more southerly location relative to the other First Nations examined.